Used cooking oil is one of the latest biofuel alternatives used by aviation companies to reduce carbon emissions. But even if it is already used in planes, critics say production will remain insufficient to make a difference on a larger scale.

Aviation is one of the fastest-growing transport sectors, with an annual growth rate of 5%. As a result, fuel consumption and carbon emissions also increase, putting the industry under pressure from regulators to find alternative ways to cut its carbon footprint.

Aviation giants like Boeing have invested heavily in supporting the development of a wide variety of sources to produce biofuels. A test project in China to turn waste cooking oil from restaurants and catering facilities – often described in China as “gutter oil” – into jet fuel is one of them.

“The aim of the project is to demonstrate technical feasibility and analyse the cost of producing higher volumes of aviation biofuels from different types of waste cooking oil,” said Annalisa Monaco, EU and NATO Director at Boeing.

“In the long-run, we believe the production of [sustainable aviation biofuel] from waste cooking oil could grow and become bigger,” Monaco told EurActiv.

The project is part of a broader collaboration between Boeing and Commercial Airplane Corp. of China (COMAC) to improve the efficiency of China’s commercial aviation system. The China pilot facility will make small quantities of aviation biofuel from “gutter oil,” about 160 gallons (650 liters) per day. Looking ahead, Boeing and COMAC estimate that 500 million gallons (1.8 billion liters) of biofuel could be made annually in China from used cooking oil.

If the project proves successful, similar plants could be considered later in Europe, Monaco said. “We started the production test in September and the normal production will continue from November on,” she said.

Biofuels have been used in 1,500 commercial flights since 2011, said Monaco, a tiny proportion compared to the 100,000 flights taking off each day across the globe.

“By 2016, our goal is to have sustainable aviation biofuels available to address 1% of global jet fuel demand, which is about 600 million gallons [2.3 billion litres],” said Monaco.

Scale and price

The aviation industry sees sustainable biofuels production – including cooking oil – as an alternative to fossil fuels. If commercial aviation were to get 6% of its fuel supply from biofuel by 2020, this would reduce its overall carbon footprint by 5%, according to the Air Transport Action Group (ATAG), an air transport industry association.

Environmental organisations, however, disagree, as some biofuels compete with food crops, causing deforestation and other harmful land use.

“While used cooking oil can be a good alternative to conventional fossil fuels from a climate perspective, there is a real question of scale and price,” said Nusa Urbancic, Programme Manager Energy at Transport & Environment, an NGO.

“Used cooking oil is three times more expensive than conventional jet fuel, and with no serious climate charges for the aviation sector, it is hard to imagine a long-term viability of this alternative.”

Boeing’s Monaco remained evasive when asked about the potential to scale up the use of cooking oil as a jet fuel. Urbancic, however, thinks the potential is limited. “People will have to eat a lot of greasy food to fuel even one trans-continental flight,” she said.

Efficiency and pricing should come first

Under the EU’s emissions-trading scheme, European airlines are requested to pay for carbon emissions on internal flights. Initially included in the scheme, foreign flights, were exempted from the law following a backlash from the US and China.

Using biofuels for the intra-EU routes offers major benefits to carriers, as biofuels will not count as emissions in aviation, and biofuel producers either receive tax incentives or subsidies.

Boeing recognises the importance of biofuels “to support the growth of the sector in a sustainable way”. The aircraft maker points to studies by the U.S. Department of Energy showing that sustainably produced biofuel reduces carbon emissions by 50-80% on a lifecycle basis compared to petroleum jet fuel.

But the sector would need “a serious carbon price to make biofuels viable for aviation”, Urbancic said. “Efficiency and pricing should come first, biofuels being the last option,” Urbanic added.

According to Boeing, concentrating on biofuels alone will not be enough to cut down emissions in aviation. Aircraft need to improve their environmental performance as well, and the EU should put in place a modernised air traffic management system to help the industry achieve its environmental goals.